JP5485191B2 - Endoscope device - Google Patents

Description

  The present invention relates to an endoscope apparatus that performs diagnosis using autofluorescence of a living body, and more particularly relates to an endoscope apparatus that is bright and that can easily identify a lesion by autofluorescence.

  For observation inside a living body by an endoscope apparatus used in the medical field, white light is incident as an observation light on an observation part of the living body, and reflected light from the living body is received by a CCD sensor or the like, and photometry is performed. So-called normal light observation (photoelectric conversion) is common.

On the other hand, in recent years, an endoscope apparatus that performs so-called autofluorescence observation using a living tissue that exists in a living body and fluoresces when irradiated with ultraviolet light to blue light is also known.
In this autofluorescence observation, light in a predetermined wavelength band is incident on an observation site of a living body as excitation light, and fluorescence generated by the living tissue by the incidence of this excitation light is measured by a CCD sensor or the like. The normal part and the lesion part in the living body differ in the intensity of the fluorescence generated by the living tissue by the incidence of excitation light. Therefore, by utilizing this autofluorescence, it is possible to identify (discriminate) the normal site and the lesion site in the living body.

As an endoscope apparatus that performs such autofluorescence observation, for example, apparatuses described in Patent Document 1 and Patent Document 2 are known.
In the apparatus described in Patent Document 1, excitation light is incident on an observation site, and reflected light and autofluorescence from the observation site are the same as the first spectral band in which autofluorescence intensity is different between a normal part and an abnormal part. The light is spectrally divided into a second spectral band having the same autofluorescence intensity and measured by a photodetector such as a CCD sensor. A pseudo color image is generated by assigning the photometric result in the first spectral band to, for example, the G (green) channel and the photometric result in the second spectral band to, for example, the R (red) channel. Perform autofluorescence observation.

  On the other hand, in the endoscope apparatus described in Patent Document 2, illumination light having a predetermined wavelength band and excitation light that emits fluorescence of biological tissue are sequentially irradiated to an observation site in a predetermined cycle. Then, an image is picked up by a CCD sensor or the like, and a first image signal by illumination light and a second image signal by autofluorescence of a living body are obtained. The first image signal and the second image signal are stored and synchronized according to the period, and one or two channels of R, G, and B (blue) channels for displaying one image signal are displayed. And assigning the other image signal to the remaining channels, a pseudo color image is generated in the same manner, and autofluorescence observation is performed.

Japanese Patent No. 3810337 JP 2006-43289 A

As described above, the intensity of autofluorescence due to the living tissue differs between the lesioned part and the normal part. Therefore, it is possible to discriminate between a lesioned part and a normal part from an image of autofluorescence observation.
However, a conventional endoscope apparatus for performing autofluorescence observation / photometry of autofluorescence of living tissue or reflected light from a living body, as shown in Patent Document 1 and Patent Document 2, Is assigned to the R, G, and B channels for display, and a pseudo color image is displayed.
Here, as is well known, the autofluorescence of living tissue has a low intensity (amount of luminescence). For this reason, in such a pseudo color image, there are many cases where a lesioned part and a normal part cannot be clearly identified.

  Moreover, since a pseudo color image is generated using an image signal of autofluorescence or an image signal of observation light in a predetermined wavelength band, compared with a normal light image using white light as observation light, , The image is dark and has low sharpness.

  An object of the present invention is to solve the above-mentioned problems of the prior art, in an endoscope apparatus for performing autofluorescence observation in which excitation light is incident to measure autofluorescence of a living tissue, by autofluorescence of the living tissue. An object of the present invention is to provide an endoscope apparatus that can clearly distinguish a lesioned part from a normal part and that can obtain a bright autofluorescent image.

  In order to achieve the above object, an endoscope apparatus of the present invention irradiates an endoscope that photoelectrically captures an in-vivo image and excitation light that excites a fluorescent component in the living body to emit fluorescence. A light source device having a fluorescence observation light source and a normal light observation light source that emits white light, and obtained by the endoscope photographing fluorescence emitted from the fluorescent component in the living body by irradiation of the excitation light. And a processing means for processing a normal light observation image taken by the endoscope by the white light irradiation using the G fluorescence signal and the R fluorescence signal.

  In such an endoscope apparatus of the present invention, it is preferable that the fluorescence observation light source emits light having a wavelength of 370 to 470 nm as the excitation light.

The processing means preferably processes the normal light observation image using an “R fluorescence signal / G fluorescence signal” obtained by dividing the R fluorescence signal by the G fluorescence signal.
In this case, the processing means multiplies at least one of the R image signal, the G image signal, and the B image signal of the normal image signal by a correction coefficient including the “R fluorescence signal / G fluorescence signal”. The normal light observation image is preferably processed, and the processing means multiplies 1 by the correction coefficient obtained by adding the “R fluorescence signal / G fluorescence signal” to the normal light observation. It is preferable to perform image processing, and it is preferable that the processing means generates the correction coefficient by multiplying the “R fluorescence signal / G fluorescence signal” by a predetermined coefficient α and then adding the result to 1. .
The processing means preferably performs processing of the normal light observation image by multiplying the correction coefficient obtained by subtracting the “R fluorescence signal / G fluorescence signal” from 1; and the processing means Preferably, the “R fluorescence signal / G fluorescence signal” is multiplied by a predetermined coefficient α and then subtracted from 1 to generate the correction coefficient.

Furthermore, the endoscope images the first solid-state imaging device for capturing a normal light observation image by the white light irradiation and the fluorescence emitted from the fluorescent component in the living body by the excitation light irradiation. And a second solid-state imaging device.
In this case, it is preferable that the endoscope forms an image on the first solid-state image sensor and the second solid-state image sensor with one imaging lens, and further, the second solid-state image sensor. It is preferable that the element captures the fluorescence emitted from the fluorescent component in the living body through a filter through which the excitation light does not pass and the fluorescence emitted from the fluorescent component in the living body passes.

The endoscope apparatus of the present invention having the above-described configuration uses the characteristic that the intensity of the autofluorescence of the green region and the autofluorescence of the red region is reversed between the lesioned portion and the normal portion, thereby Can be emphasized. In addition, using this characteristic, the lesion area is emphasized using the characteristic based on normal light observation, so that an autofluorescence image having the same brightness as the normal light observation image can be generated. .
Therefore, according to the present invention, it is possible to accurately distinguish between a lesioned part and a normal part by using a bright autofluorescent image and to perform an appropriate diagnosis.

It is a schematic perspective view of an example of the endoscope apparatus of the present invention. It is a block diagram which shows notionally the structure of the endoscope apparatus shown in FIG. It is a block diagram which shows notionally the process part of the endoscope apparatus shown in FIG. It is an example of the autofluorescence spectrum which a lesioned part and a normal part of a biological body produce.

  Hereinafter, an endoscope apparatus of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

  FIG. 1 shows a schematic perspective view of an example of the endoscope apparatus of the present invention, and FIG. 2 conceptually shows the configuration of the endoscope apparatus shown in FIG.

An endoscope apparatus 10 in the illustrated example includes an endoscope 12, a processor device 14 that performs processing of an image captured by the endoscope 12, and observation light for performing observation (imaging) with the endoscope 12. And a light source device 16 for supplying excitation light.
The processor device 14 is connected with a display device 18 that displays an image captured by the endoscope and an input device 20 for inputting various instructions. The processor device 14 may further be connected to a printer (recording device) that outputs an image captured by the endoscope as a hard copy.
The endoscope apparatus 10 of the present invention is so-called normal light observation in which white light is used as observation light, and so-called autofluorescence in which excitation light is incident on an observation site and the autofluorescence of a living tissue is measured to form an image. This is an apparatus capable of performing observation (hereinafter referred to as fluorescence observation).

As shown in FIG. 2, the endoscope 12 is a so-called electronic endoscope that photoelectrically captures an in-vivo image using an image sensor such as a CCD sensor 48. The endoscope 12 includes an insertion portion 26, an operation portion 28, a universal cord 30, a connector 32, and a video connector 36, similarly to a normal endoscope.
At the time of observation (diagnosis), the endoscope 12 has a video connector 36 connected to the connecting portion 14a of the processor device 14 and a connector 32 connected to the connecting portion 16a of the light source device 16. Note that the connector 32 is connected to a suction means or an air supply means for sucking or supplying an observation site, a water absorption means for injecting water to the observation site, or the like, as in a normal endoscope.

  Similarly to a normal endoscope, the insertion portion 26 of the endoscope 12 includes a long flexible portion 38 on the proximal end side, a scope portion at the distal end where the CCD sensor 48 and the like are disposed (the distal end portion of the endoscope). ) 42, and a bending portion (angle portion) 40 between the flexible portion 38 and the scope portion 42, and the operation portion 28 is taken with an operation knob 28 a or a still image for bending the bending portion 40. A shooting button or the like is provided.

  As conceptually shown in FIG. 2, the scope unit 42 includes a photographing lens 46, a CCD sensor 48, a high sensitivity CCD sensor 50, an excitation light cut filter 52, a half mirror 54, an illumination lens 56, an optical fiber 58, and a lens. A cover glass (not shown) or the like is arranged to protect the etc.

Although not shown, the endoscope 12 includes a forceps channel for inserting various treatment tools such as forceps, a forceps port, an air supply / water supply channel for performing suction, air supply, water supply, and the like. Air / water outlets are also provided.
The forceps channel passes through the bending portion 40 and the flexible portion 38 and communicates with a forceps insertion opening provided in the operation portion 28, and the air / water supply channel includes the bending portion 40, the flexible portion 38, the operation portion 28, and the universal cord 30. And communicates with the connection portion of the connector 32 with the suction means, air supply means, and water supply means.

The optical fiber 58 is inserted through the bending portion 40, the flexible portion 38, the operation portion 28, and the universal cord 30 to the connector 32 connected to the light source device 16.
White light and excitation light emitted by the light source device 16 to be described later are incident on the optical fiber 58 from the connector 32 and propagated through the optical fiber 58, and in the scope unit 42, from the tip of the optical fiber 58, an illumination lens. 56 is incident on the observation region by the illumination lens 56.

  Further, an image of the observation site irradiated with the observation light (reflected light by the living body) is taken by the CCD sensor 48. In addition, autofluorescence (hereinafter referred to as fluorescence) emitted from the living tissue at the observation site by the irradiation of excitation light is photographed by the high-sensitivity CCD sensor 50.

The CCD sensor 48 is used in general endoscopes and digital cameras that take (capture) color images by measuring R (red) light, G (green) light, and B (blue) light. It is a normal color CCD sensor. Accordingly, the CCD sensor 48 outputs R image, G image, and B image signals.
On the other hand, the high-sensitivity CCD sensor 50 (hereinafter referred to as the high-sensitivity sensor 50) measures R light and G light, and can detect a weak (low light) incident light and output a signal, and is a highly sensitive CCD sensor. It is. Accordingly, an R image and a G image are output from the high sensitivity sensor 50.
The scope unit 42 including the CCD sensor 48 and the high sensitivity sensor 50 will be described in detail later.

In the present invention, the imaging device is not limited to the CCD sensor 48, and various known imaging devices such as a CMOS image sensor can be used.
The high-sensitivity sensor 50 uses a high-sensitivity CCD sensor that measures R light, G light, and B light in the same manner as a normal color CCD sensor, and outputs only the output signals of the R and G pixels. By using it, you may make it perform the fluorescence observation mentioned later.

  Output signals from the CCD sensor 48 and the high-sensitivity sensor 50 are sent from the scope section 42 to the video connector 36 through the bending section 40, the flexible section 38, the operation section 28, the universal cord 30, and the connector 32 by signal lines.

In the illustrated example, an AFE (Analog Front Eend) substrate 64 is disposed on the video connector 36.
For example, a correlated double sampling circuit, an amplifier (automatic gain control circuit), and an A / D converter are arranged on the AFE substrate 64. The output signals of the CCD sensor 48 and the high sensitivity sensor 50 are subjected to noise removal by phase double sampling and amplification by an amplifier on the AFE substrate 64. Further, the analog signal is converted into a digital signal by the A / D converter, and is output as a digital image signal to the processor device 14 (a DSP 72 described later).
In the endoscope apparatus of the present invention, these processes may be performed not by the video connector 36 but by the connector 32 or by the processor device 14.

As described above, in the endoscope apparatus 10, the connector 32 of the endoscope 12 is connected to the connection portion 16 a of the light source device 16.
The light source device 16 supplies observation light for performing observation in a living body and excitation light for causing the living tissue to emit fluorescence to the endoscope 12. As described above, the observation light and the excitation light supplied from the light source device 16 to the endoscope 12 are incident on the optical fiber 58 from the connector 32 and propagated to the observation site from the scope portion 42 at the distal end of the insertion portion 26. Irradiated.

  As conceptually shown in FIG. 2, in the endoscope apparatus 10, the light source device 16 includes a white light source 60 that emits white light, an excitation light source 62 that emits excitation light for performing fluorescence observation, And optical fibers 60s and 62a.

The white light source 60 emits white light which is observation light used for normal light observation in a so-called endoscope.
Therefore, in the endoscope apparatus 10 in the illustrated example, normal light observation using white light as observation light is performed by using only the white light source 60 and taking an image only with the CCD sensor 48 which is a color CCD sensor. Can be done.

The white light source 60 is not particularly limited, and various types of light sources that can emit white light, such as xenon lamps and natural light LEDs, that are used in endoscope devices and the like can be used.
In addition, the phosphor is excited by light of a first wavelength band emitted from a light source, as exemplified in Japanese Patent Application Laid-Open No. 2009-56248 by the applicant of the present application, to generate light of a second wavelength band, A light source (light source device) that generates white illumination light by mixing light in the first and second wavelength bands can also be suitably used as the white light source 60.

As a white light source 60 using such a phosphor, as an example, a laser light source of B light having a central wavelength of 445 nm, and a plurality of types of fluorescent light that absorbs part of the B light and emits light in green to yellow excitation. Examples of the light source include a body (for example, a YAG-based phosphor or a phosphor such as BAM (BaMgAl ₁₀ O ₁₇ )).
In this white light source, the green to yellow light emitted by the phosphor excited by the B light and the B light transmitted without being absorbed by the phosphor are combined to obtain pseudo white light.

In addition, by combining a white light source using a phosphor with a blue-violet laser light source having a center wavelength of 405 nm, so-called special light observation (narrow-band light observation) using narrow-band light as observation light is performed. It can also be done.
This blue-violet laser light source having a central wavelength of 405 nm is transmitted through the phosphor without being absorbed. Therefore, by using this blue-violet laser light source in combination, the narrow-band light of blue-violet light is added to the white light as the observation light, and special light imaging with the narrow-band light becomes possible. In addition, with the B laser light source turned on, the blue-violet laser light source is turned on / off (high output lighting / low output lighting) at a predetermined cycle, thereby enabling normal light observation and special light observation. (Omitted) Can be performed simultaneously.

  On the other hand, the excitation light source 62 excites biological tissues in the living body, for example, porphyrin, NADH (reduced form of nicotinamide adenine dinucleotide), NADPH (reduced form of nicotinamide adenine dinucleotide phosphate), FAD (flavin adenine dinucleotide) and the like. This is a light source that emits excitation light and emits fluorescence.

The excitation light is not particularly limited, and all light having a wavelength that can excite living tissue to emit fluorescence can be used.
Among them, light having a wavelength of 370 to 470 nm (light having a peak (maximum intensity) in this wavelength range) is preferable in that the reverse characteristics of the emission intensity of R fluorescence and G fluorescence by a living tissue to be described later can be suitably expressed. It is preferably used as excitation light. In particular, light having a wavelength of 400 to 450 nm can be used more suitably in terms of ensuring the safety to the living body in addition to the expression of the reverse characteristics.

As the excitation light source 62, any of various light sources that can irradiate excitation light that generates fluorescence on a living tissue with sufficient intensity can be used.
As an excitation light source 62, various laser light sources, such as LD which has a peak in the said wavelength range, are illustrated suitably as an example. Further, a light source using a white light source such as a xenon lamp and a filter that transmits light in a predetermined wavelength band corresponding to the excitation light as shown in the above-mentioned Patent Document 2 can also be used as the excitation light source 62. It is.

White light irradiated by the white light source 60 (observation light for normal light observation) is propagated by the optical fiber 60a, supplied from the connection portion 16a to the connector 32 of the endoscope 12, and supplied from the connector 32 to the optical fiber 58. Is done. On the other hand, the excitation light irradiated by the excitation light source 62 is propagated by the optical fiber 62a, and is similarly supplied from the connector 16a to the connector 32 of the endoscope 12, and is supplied from the connector 32 to the optical fiber 58.
As described above, the white light and the excitation light supplied to the optical fiber 58 are propagated toward the optical fiber 58, are emitted from the end of the optical fiber 58 on the scope unit 42 side, and are illuminated by the illumination lens 56. Irradiated to the observation site in the living body.

The image of the observation site irradiated with the observation light (reflected light by the living body) and the fluorescence emitted from the living tissue of the observation site by the irradiation of the excitation light are detected by the CCD sensor 48 and the high sensitivity by the photographing lens 46 and the half mirror 54. An image is formed on the sensor 50 and photographed.
In other words, the half mirror 54 is disposed on the optical axis of the imaging lens 46 in the scope unit 42. The light passing through the half mirror 54 is incident / imaged on the CCD sensor 48, the light reflected by the half mirror 54 is incident on the excitation light cut filter 52, and light having a wavelength other than the excitation light passes through. The light is incident / imaged on the high-sensitivity sensor 50.

As the excitation light cut filter 52, various types of filters that shield the excitation light and transmit light having a wavelength longer than the excitation light (at least a wavelength region including the R light region) can be used.
As an example, a filter that shields light having a wavelength less than or equal to the maximum wavelength of excitation light and transmits light on a longer wavelength side exceeding the maximum wavelength of excitation light is exemplified. For example, when the excitation light source 62 is a laser light source such as an LD, a filter that shields light having a center wavelength of +20 nm or less, preferably light having a center wavelength of +10 nm or less, and transmits light having a longer wavelength than that is transmitted. Illustrated. That is, if the excitation light source 62 is a laser light source having a center wavelength of 400 nm, light having a wavelength of 420 nm or less is shielded (preferably light having a wavelength of 410 nm or less is shielded), and light having a longer wavelength side is blocked. The excitation light cut filter 52 which permeate | transmits is illustrated.
Further, when the excitation light is excitation light generated by a band limiting filter as shown in Patent Document 2, there are various known excitation light cut filters as shown in Patent Document 2, Is available.

  When normal light observation is performed in the endoscope apparatus 10, the light source device 16 continuously irradiates white light (observation light) from only the white light source 60 and performs imaging using only the CCD sensor 48. Thus, the normal light observation image is taken in the same manner as the normal light observation in the normal endoscope apparatus.

On the other hand, when performing fluorescence observation, the light source device 16 alternately turns on the white light source 60 and the excitation light source 62 with a predetermined period under the control of the control unit 14b of the processor device 14 described later ( Drive). That is, when performing fluorescence observation in the endoscope apparatus 10, white light, which is observation light for performing normal light observation, and excitation light for performing fluorescence observation are alternately observed at a predetermined cycle. The site is irradiated.
Note that the cycle of alternating lighting of the white light source 60 and the excitation light source 62 may be appropriately set according to the sensitivity of the sensor, the imaging region, and the like.

  When performing fluorescence observation, the endoscope 12 performs imaging (sampling) with the CCD sensor 48 when the white light source 60 emits white light under the control of the control unit 14b. When the light source 62 is irradiating excitation light, the high sensitivity sensor 50 performs imaging. That is, in the case where fluorescence observation is performed in the endoscope apparatus 10, a normal light image at the CCD sensor 48 according to the alternate lighting of the white light source 60 and the excitation light source 62 in the predetermined period (synchronously). The photographing of (R image, G image and B image) and the photographing of the fluorescence image (R image and G image) by the high sensitivity sensor 50 are alternately performed.

In the present invention, the distribution of the optical path (light) to the CCD sensor 48 and the high sensitivity sensor 50 is not limited to the configuration performed by the half mirror 54. For example, the optical path may be distributed to the CCD sensor 48 and the high-sensitivity sensor 50 by putting a total reflection mirror in and out of the optical path.
Moreover, the endoscope used in the endoscope apparatus 10 of the present invention distributes the optical path to the CCD sensor 48 and the high sensitivity sensor 50 as shown in the example of the drawing, and transmits normal light to one photographing lens 46. There is no limitation on the configuration of a so-called 1-lens 2 sensor provided with two imaging elements for observation and fluorescence observation. For example, if the normal light observation image and the fluorescence image of the same observation site can be alternately photographed at a predetermined cycle, an imaging lens corresponding to each of the image sensor for normal light observation and the image sensor for fluorescence observation is used. The structure of the provided 2 lens 2 sensor may be sufficient.
Alternatively, if the image sensor has sufficient sensitivity, a filter turret having, for example, an unplugged portion and an excitation light cut filter is provided between the imaging lens and the image sensor as one lens / one sensor. You may make it perform light observation and fluorescence observation alternately.
That is, the endoscope apparatus 10 according to the present invention has various configurations as long as the configuration allows the normal light observation with white light and the fluorescence observation with the excitation light cut off alternately (imaging) at the same observation site. Is available.

  As described above, the output signals of the CCD sensor 48 and the high-sensitivity sensor 50 are sent to the video connector 36 and subjected to processing such as A / D conversion by the AFE 64, and a digital image (digital image signal (image data / Image information)) is supplied to the processor device 14 (its processing unit 14a).

The processor device 14 performs predetermined processing on the normal light observation image and the fluorescence image supplied (output) from the endoscope 12 (hereinafter, collectively referred to as “image” when there is no need to distinguish both). Are displayed on the display device 18 as an image photographed by the endoscope 12, and the endoscope device 10 is controlled.
In the illustrated example, the processor device 14 includes an image processing unit 14a and a control unit 14b that controls the entire endoscope apparatus 10 including the processor device 14 itself.

FIG. 3 conceptually shows the image processing unit 14a in the processor device 14 with a block diagram.
As illustrated in FIG. 3, the processing unit 14 a includes a DSP 72, a storage unit 74, an image generation unit 76, a fluorescence image processing unit 78, and a display image generation unit 80.

In the processor device 14, the image supplied from the endoscope 12 is supplied to the DSP 72.
The DSP 72 is a well-known DSP (Digital Signal Processor), and performs predetermined processing such as gamma correction and color correction processing on the supplied image, and then stores it in a predetermined area of the storage unit (memory) 74.

  When the image is stored in the storage unit 74, the image generation unit 76 or the fluorescence image processing unit 78 reads the image and performs a predetermined process.

The fluorescence image processing unit 78 includes a reading unit 84 and an R _F / G _F calculation unit 86. The fluorescence image processing unit 78 works only when performing fluorescence observation.
Reading portion of the fluorescent image processing unit 78 84, under the control of the control unit 14b, in an image captured in the storage unit 74 by the high-sensitivity sensor 50 is stored, reads the image, R _F / G _F calculation unit 86. As described above, the high-sensitivity sensor 50 measures R light and G light, and what is photographed is a (self-generated) fluorescent image emitted by a living tissue upon incidence of excitation light. Thus, the read section 84 reads out, to supply to the R _F / G _F calculation unit 86 is a fluorescence image G _F fluorescence image R _F and G R.
R _F / G _F calculation unit 86 uses the supplied fluorescent image R _F and the fluorescence image G _F, the R _F / G _F is the ratio between the fluorescence image R _F and the fluorescence image G _F and calculates , And supplied to the fluorescence processing unit 92 of the image generation unit 76 described later.

On the other hand, the image generation unit 76 includes a reading unit 90, a fluorescence processing unit 92, and an image correction unit 94.
The reading unit 90 of the image generation unit 76 reads an image when an image photographed by the CCD sensor 48 is stored in the storage unit 74 under the control of the control unit 14b. As described above, the CCD sensor 48 is a normal color CCD sensor, and a normal light image is captured. Therefore, the reading unit 84 reads out the R normal image R _N , the G normal image G _N , and the B normal image B _N.

The fluorescence processing unit 92 operates only when performing fluorescence imaging. Therefore, in the normal light observation, the read section 84 is read, normal image R _N, the normal image G _N and the normal image B _N, what the fluorescent processor 92 also processes also conducted without the (fluorescent processing unit 92 As it is, it is supplied to the image correction unit 94 as an R image R _D , a G image G _D , and a B image B _D as it is.
The image correction unit 94 performs color conversion processing such as 3 × 3 matrix processing, gradation conversion processing, and three-dimensional LUT processing on the R, G, and B images; Color emphasis processing that emphasizes the direction of the color difference between blood vessels and mucous membranes rather than the average color of the image so that the blood vessels can be easily seen; Image structure enhancement processing such as sharpness processing and contour enhancement; etc. The image is corrected and sent to the display signal generation unit 80 as an image corresponding to display.

In contrast, when performing the fluorescence observation, reading unit 84 is read, normal image R _N, the normal image G _N and the normal image B _N, after performing predetermined processing with fluorescent processing unit 92, the image R _D, as an image G _D and image B _D, and supplied to the image correction unit 94, perform the previous similar image correction, as an image corresponding to the display, and sends the display signal generation unit 80.

The fluorescence processing unit 92 includes an R image processing unit 92r, a G image processing unit 92g, and a B image processing unit 92b. Each image processing unit, the time of fluorescence observation, the normal image (each pixel), R corresponding to the pixels of the R _F / G _F (usually image R _F / G _F calculation unit 86 has calculated _F / G _F) and performs a process using the processes of the R image processing unit 92r includes normal image R _N images R _D of R, G image processing section 92g processes the normal image G _N G the image G _D, B image processing unit 92b is the image B _D B-handling normal image B _N, respectively, to produce.

なお、上記式において、αは、好ましい態様として用いられるものであり、病変部におけるＲ_F／Ｇ_Fが１に近づき、好ましくは、さらに正常部におけるＲ_F／Ｇ_Fが０に近づくように、適宜、設定された係数である。 Specifically, in the illustrated example, each image processing unit of the fluorescence processing unit 92 processes the normal image with R _F / G _{F according} to the following formula, and the image R _D , the image G _D, and the image B _{D are} processed. Is generated.

In the above formula, alpha is one used as a preferred embodiment, approaches R _F / G _F is 1 in the lesion, as preferably, approaches R _F / G _F is 0 in still normal portion, The coefficient is set as appropriate.

FIG. 4 shows a (auto) fluorescence spectrum of a living tissue when light irradiated from a laser light source having a central wavelength of 380 nm is irradiated as an excitation light on a living body (human large intestine mucosa).
In FIG. 4, the horizontal axis indicates the fluorescence wavelength, the vertical axis indicates the fluorescence intensity, and the normal line indicates the fluorescence at the lesioned part and the broken line indicates the fluorescence at the normal part.

Fluorescence in the fluorescence generated upon incidence of a B light or violet light as excitation light, fluorescent R _F of R is the fluorescence mainly due to porphyrins, fluorescent G _F of G is mainly due to NADH or NADPH It is thought that.
Here, when the fluorescence R _F of R is seen, for example, as shown in the fluorescence characteristics near 630 nm, the normal part does not show so strong fluorescence, but the lesion part has very strong fluorescence. In contrast, the fluorescence G _F of G, for example, as shown in the fluorescence characteristics near 470～530Nm, exhibit strong fluorescence in normal portion, the lesion, less, strong fluorescence is not shown. That is, the fluorescence R _F and the fluorescence G _F generated by the living tissue when the B light is incident as excitation light have opposite characteristics in the normal part and the lesion part.

By utilizing the reverse characteristics of the fluorescence R _F and the fluorescence G _F between the lesion and the normal part, the lesion can be emphasized.
That is, in the lesions, since the fluorescence R _F is a fluorescent G _F is weak in strength R _F / G _F is greater, the normal portion, conversely, fluorescent R _F is a fluorescent G _F is strong in weak Therefore, R _F / G _F becomes smaller. Thus, by using this, a normal image, as appropriate, to the selected color, multiplying R _F / G _F, adds, by performing processing such as subtraction, enhancement and the normal portion of the lesion in the normal image It is possible to obtain an image in which the affected area is emphasized by performing suppression of the above.

Here, in the illustrated example, a preferred embodiment, the lesions R _F / G _F increases, approaches R _F / G _F is 1, the normal unit R _F / G _F decreases, R _F / G A coefficient α set so that _F approaches 0 is used.
Also, the R image, and calculates the image R _D is multiplied by the normal image R _N by adding the α × R _F / G _F 1. On the other hand, for the G image and the B image, α × R _F / G _F is subtracted from 1 and multiplied by the normal image _GN and the normal image B _N to calculate the image _GD and the image _BD , respectively. Yes.

Therefore, since the normal image processed by the fluorescence processing unit 92 is R _F / G _F is 0 (a value close to 0) in the normal part, both the R, G, and B images are normal images. 1 (a value close to 1) is multiplied. Therefore, in the normal portion, and outpatient image, the image R _D, between the image G _D and image B _D, a large change in the image is not.
In contrast, the normal image that has been processed by the fluorescent processing section 92, the lesion, normal image R _N 2 (close to 2) is multiplied to the image R _D is emphasized normal image R _N double The resulting image. Further, in the lesions, the normal image G _N and the normal image B _N, both 0 (value close to 0) so are multiplied, the image G _D and image B _D are both an image close to 0.
That is, in this example, an image in which a lesion is highlighted in red with respect to a normal part is obtained.

As apparent from the above description, according to the present invention, by utilizing the inverse characteristic of the fluorescent R _F and fluorescence G _F at the normal portion and the lesion, a fluorescence image (normal image, processing a fluorescent image In the image), the lesion can be highlighted with a predetermined color. In addition, since the highlight display using the fluorescent image is performed based on the normal light observation image, the fluorescent image can be displayed with the same brightness as a general normal light observation image.
Therefore, according to the endoscope apparatus of the present invention, it is possible to accurately distinguish between a lesioned part and a normal part with a bright fluorescent image in which the lesioned part is emphasized.

As described above, the coefficient alpha, the process of the normal image using the R _F / G _F under fluorescent processing unit 92, which is used as a preferred embodiment, R _F / G _F in lesion approaches 1 Thus, the coefficient is set as appropriate. More preferably, the coefficient alpha, approaches R _F / G _F is 1 in the lesion, further, so as to approach the R _F / G _F is 0 in the normal section, as appropriate, a coefficient set.
By using such a coefficient α, an image of each color can be prevented from becoming unnecessarily large / small, and a suitable lesion can be emphasized with a better balance.

Such a coefficient α is determined by the spectral sensitivity characteristics of the high-sensitivity sensor 50 (the band characteristics of the filter and the (spectral) sensitivity of the element), the wavelength of the excitation light irradiated by the light source device 16 (spectral characteristics), and the excitation light cut filter 52. Depending on the device characteristics of the endoscope 12 and the light source device 14, such as spectral characteristics (filter characteristics), a coefficient α is set as appropriate so that R _F / G _F approaches 1 (becomes 1) at the lesion. That's fine. Preferably, according to the apparatus characteristics, approaches R _F / G _F 1 in the lesion, and the R _F / G _F approaches 0 (the 0) such coefficient α in normal unit, as appropriate, You only have to set it.

In the above example, for the R image, α × R _F / G _F is added to 1 to calculate the image _RD (hereinafter, such processing is simply referred to as “addition”), and for the G image and the B image, α × R _F / G _F is subtracted from 1 to calculate an image _GD and an image _BD (hereinafter, such processing is simply referred to as “subtraction”), and the lesion is highlighted in red.
However, the present invention is not limited to this, and the fluorescence processing unit 92 can use various normal image addition and subtraction processes.

As an example, as shown below, the R image and the B image may be subtracted and the G image may be added. According to this process, the lesion is highlighted in green.

Alternatively, as shown below, the R image and the G image may be subtracted and the B image may be added. According to this process, the lesion is highlighted in blue.

Alternatively, as shown below, the R image and the G image may be added and the B image may be subtracted. According to this process, the lesion is highlighted in yellow.

Alternatively, as shown below, the R image and the B image may be added, and the G image may be subtracted. According to this processing, the lesioned part is emphasized in magenta.

Alternatively, as described below, the R image may be subtracted, and the B image and the G image may be added. According to this process, the lesioned part is emphasized in cyan.

Or as shown below, you may make it subtract all R image, B image, and G image. According to this processing, the lesioned part is displayed darker than the normal part.

Further, as shown below, all of the R image, the B image, and the G image may be added. According to this process, the lesioned part is displayed brighter than the normal part.

As described above, the coefficient α is used as a preferred embodiment and is not necessarily used. Further, depending on the device characteristics of the endoscope apparatus 10 as described above, R _F / G _{F at the} lesioned part is close to 1 without using the coefficient α, or R _F / G at the normal part. _F becomes a value close to 0.
Further, it is not limited to adding / subtracting R _F / G _F to 1 to process the normal images R _N , G _N and B _N , and R _F / G _F is multiplied by the normal image as it is, The images R _D , G _D and B _D may be calculated. Alternatively, the images R _D , G _D, and B _D may be calculated by adding or subtracting R _F / G _{F as it} is to the normal image.

Further, in the above example, all of the R image, the G image, and the B image are processed with the correction coefficient including R _F / G _F to calculate the images R _D , G _D, and B _D. However, the present invention is not limited to this.
For example, in (operation as shown in the numerical formula 1 8) a process as described above, adds the R _F / G _F in R images (1 + multiplying R _F / G _F), R _F is a G image The image R _D , G _D and B _D may be calculated without subtracting / G _F (multiplying 1−R _F / G _F ) and performing any processing on the B image. Alternatively, R _F / G _F may be added only to the color to be emphasized.

As described above, the normal images R _N , G _N and B _N read by the reading unit 90 are not subjected to any processing in the fluorescence processing unit 92 in the case of normal light observation, and the images R _D , G _D and _BD is supplied to the image correction unit 94. In the case of fluorescence observation, the normal images R _N , G _N and B _N read by the reading unit 90 are processed by R _F / G _F in the fluorescence processing unit 92, and then the images R _D , G _D and _BD is supplied to the image correction unit 94.
The images R _D , G _D, and B _D are subjected to predetermined processing such as color conversion processing and image structure enhancement processing in the image correction unit 94, and then displayed as display images (normal light observation image / fluorescence image). Is supplied to the display image generation unit 80.

The display signal generation unit 80 performs necessary processing such as color space conversion and enlargement / reduction on the normal light observation image and the fluorescence image supplied from the image generation unit 76, and also assigns the image and determines the subject's subject. Necessary processing such as incorporation of character information such as a name is performed to generate a display image in which a normal light observation image or a fluorescence image is incorporated, and this image is displayed on the display device 18.
Note that the endoscope apparatus 10 of the present invention is not limited to displaying only the normal light observation image and displaying only the fluorescence image, and the fluorescence image processed by the fluorescence processing unit 92 and the fluorescence processing unit 92 are used. The normal light observation images that are not processed may be displayed side by side (parallel display), or the fluorescent image and the normal light observation image may be toggled and displayed. Further, two or more of the display of the fluorescent image, the display of the normal light image, the parallel display, and the switching display may be selected as the display mode.

Hereinafter, an example of the operation of the endoscope apparatus 10 will be described taking the case of performing fluorescence observation as an example.
When the input device 20 instructs to start photographing with the endoscope 12, the light source device 16 alternately turns on the white light source 60 and the excitation light source 62 at a predetermined cycle. At the same time, in the endoscope 12, the CCD sensor 48 and the high sensitivity sensor 50 start photographing.
The white light irradiated from the white light source 60 is propagated by the optical fiber 60a, and the excitation light irradiated by the excitation light source is propagated by the optical fiber 62a, and both are connected to the connector 32 of the endoscope 12 from the connection portion 16b. Supplied.

The white light and the excitation light supplied to the connector 32 of the endoscope 12 are propagated to the scope unit 42 by the optical fiber 58, and are emitted from the tip of the optical fiber 58 in the scope unit 42, to the observation site of the living body. Irradiated.
When white light is irradiated, the CCD sensor 48 takes an image, and R, G, and B images of the observation site (light reflected by the living body) are output. In addition, when the excitation light is irradiated, the high-sensitivity sensor 50 performs imaging, and R and G images of fluorescence emitted from the living tissue at the observation site are output.

Output signals from both sensors are supplied to the AFE substrate 64. The AFE board 64 performs noise removal, amplification, A / D conversion, and the like on the output signals of both sensors, and the result is sent to the DSP 72 of the processor device 14 (processing unit 14a) as a digital image signal. Supply.
The DSP 72 performs predetermined processing such as gamma correction and color correction processing on the supplied image (image signal), and then stores the processed image in a predetermined portion of the storage unit 74.

When the image signal is stored in the storage unit 74, the R fluorescence image R _F and the G fluorescence image G _F taken by the high-sensitivity sensor 50 are read by the reading unit 84 of the fluorescence image processing unit 78, and R _F / It supplies the G _F calculation unit 86.
Further, the R _F / G _F calculation unit 86 calculates R _F / G _F and supplies it to the fluorescence processing unit 92 (the R image processing unit 92r, the G image processing unit 92g, and the B image processing unit 92b).

On the other hand, the R normal image R _N , the G normal image G _N , and the B normal image B _N captured by the CCD sensor 48 are read by the reading unit of the image generation unit 76 and supplied to the fluorescence processing unit 92.
The fluorescent unit 92, the R image processing unit 92r normal image R _N, the G image processing unit 92g is a normal image G _N, B image processing unit 92b is the normal image B _N, respectively, the above equations shown below It was treated with R _F / G _F, the image R _D, the image G _D and image B _D, is calculated.

The image R _D , the image G _D, and the image B _D obtained by the fluorescence processing unit 92 are then subjected to predetermined image correction such as color conversion processing and image structure processing in the image correction unit 94 to be displayed. The image is displayed on the display image generation unit 80 and is displayed on the display device 18 by the display image generation unit 80 as a fluorescent image.
As described above, the display image is an image obtained by highlighting a lesion part taken by fluorescence observation in red as a basis of the normal light observation image, so that the normal part and the lesion part can be easily recognized, and It is an image having the same brightness as the normal light observation image.

  Although the endoscope apparatus of the present invention has been described in detail above, the present invention is not limited to the above-described example, and various improvements and modifications may be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Endoscope 12 Endoscope 14 Processor apparatus 16 Light source apparatus 18 Display apparatus 20 Input apparatus 26 Insertion part 28 Operation part 30 Universal code 32 Connector 36 Video connector 38 Flexible part 40 Bending part 42 Scope part 46 Shooting lens 48 CCD sensor DESCRIPTION OF SYMBOLS 50 High sensitivity (CCD) sensor 52 Excitation light cut filter 54 Half mirror 56 Illumination lens 58, 60a, 62a Optical fiber 60 White light source 62 Excitation light source 64 AFE substrate 72 DSP
74 Storage Unit 76 Image Generation Unit 78 Fluorescence Image Processing Unit 80 Display Image Generation Unit 80, 84 Reading Unit 86 R _F / G _F Calculation Unit 92 Fluorescence Processing Unit 94 Image Correction Unit

Claims (8)

An endoscope that photoelectrically captures in-vivo images;
A light source device having a fluorescence observation light source for irradiating excitation light having a wavelength of 370 to 470 nm for exciting fluorescent components in a living body to emit fluorescence, and a normal light observation light source for irradiating white light;
Using the G fluorescence signal and the R fluorescence signal obtained by the endoscope photographing the fluorescence emitted by the fluorescent component in the living body by the excitation light irradiation, the endoscope is irradiated by the white light irradiation. Processing means for processing the photographed normal light observation image ,
The processing means uses the “R fluorescence signal / G fluorescence signal” obtained by dividing the R fluorescence signal by the G fluorescence signal, and uses the R image signal, G image signal, and B image signal of the normal light observation image. By multiplying at least one of the R image signal, the G image signal, and the B image signal by multiplying at least one of them by a correction coefficient including the “R fluorescence signal / G fluorescence signal”, An endoscope apparatus for processing the normal light observation image . 2. The endoscope apparatus according to claim 1 , wherein the processing unit performs processing of the normal light observation image by multiplying 1 by a correction coefficient obtained by adding the “R fluorescence signal / G fluorescence signal”. The endoscope apparatus according to claim 2 , wherein the processing unit multiplies the “R fluorescence signal / G fluorescence signal” by a predetermined coefficient α, and then adds the value to 1 to generate the correction coefficient. The said processing means performs the process of the said normal light observation image by multiplying the correction coefficient obtained by subtracting the said "R fluorescence signal / G fluorescence signal" from 1 . Endoscopic device. The endoscope apparatus according to claim 4 , wherein the processing unit multiplies the “R fluorescence signal / G fluorescence signal” by a predetermined coefficient α, and then subtracts from 1 to generate the correction coefficient. The endoscope includes a first solid-state imaging device for capturing a normal light observation image by irradiation with the white light;
The endoscope apparatus according to any one of claims 1 to 5 , further comprising a second solid-state imaging device for imaging fluorescence emitted from the fluorescent component in the living body by irradiation of the excitation light. The endoscope apparatus according to claim 6 , wherein the endoscope forms an image on the first solid-state imaging device and the second solid-state imaging device with a single imaging lens. The second solid-state imaging device photographs fluorescence emitted from the fluorescent component in the living body through a filter through which the excitation light does not pass and fluorescence emitted from the fluorescent component in the living body passes. The endoscope apparatus according to claim 6 or 7 .

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